Betty Neuman's Systems Model
(written by and reprinted with the kind permission of Jacqueline Fawcett, RN, PhD, FAAN)
Neuman's work is a conceptual model that views the patient as an open system in interaction with the environment. The patient system is a composite of five interrelated variables:
PHYSIOLOGICAL variables refer to bodily structure and function.
PSYCHOLOGICAL variables refer to mental processes and relationships.
SOCIOCULTURAL variables refer to social and cultural functions.
DEVELOPMENTAL variables refer to the developmental processes of life.
SPIRITUAL variables refer to aspects of spirituality on a continuum from complete unawareness or denial to a consciously developed high level of spiritual understanding.
The patient system is depicted as a central core surrounding by concentric rings.
The CENTRAL CORE is a basic structure of survival factors common to the species, such as variables contained within, innate or genetic features, and strength and weakness of the system parts, such as temperature range, genetic response patterns, ego structure, strengths and weaknesses of body organs and cognitive ability.
The CONCENTRIC RINGS represent three mechanisms that protect the basic structure.
The outermost ring is the FLEXIBLE LINE OF DEFENSE. This mechanism is a protective buffer for the patient's normal or stable state. Ideally, it prevents invasion of stressors and keeps the patient system free from stressor reactions or symtomatology. The flexible line of defense is thought of as a dynamic, accordion-like mechanism, rapidly expanding away from or drawing closer to the normal line of defense. When the flexible line is expanded away from the normal line of defense, greater protection against stressor invasion is provided; when it draws closer to the normal line, less protection is provided.
The NORMAL LINE OF DEFENSE lies between the flexible line of defense and the lines of resistance. The normal line of defense is the patient system's normal or usual wellness state. It reflects what the patient has become or evolved to over time and is the result of adjustment between patient system variables and environmental stressors. Expansion of the normal line of defense reflects an enhanced wellness state; contraction, a diminished state of wellness.
The innermost rings are the LINES OF RESISTANCE. These lines are involuntarily activated when a stressor invades the normal line of defense. The lines of resistance attempt to stabilize the patient system and foster a return to the normal line of defense. These lines contain internal factors that support the basic structure and the normal line of defense, such as mobilization of white blood cells. If the lines of resistance are effective, the system can reconstitute; if they are ineffective, death may ensue.
ENVIRONMENT is defined as all internal and external actors or influences surrounding the patient system. Three relevant environments have been identified by Neuman.
The INTERNAL ENVIRONMENT consists of all forces or interactions influence internal to or contained solely within the boundaries of the defined patient system. It is the source of intrapersonal stressors.
The EXTERNAL ENVIRONMENT consists of all forces or interactions influence external to or exist outside the defined patient system. It is the source of interpersonal extrapersonal stressors.
The CREATED-ENVIRONMENT is subconsciously developed by the patient as a symbolic expression of system wholeness. It supersedes and encompasses the internal and external environments.
The goal of NURSING to facilitate optimal wellness through retention, attainment, or maintenance of patient system stability by means of primary, secondary, or tertiary prevention.
PRIMARY PREVENTION is described as the action required to retain patient system stability. Interventions involving primary prevention is selected when the risk of or hazard from a stressor is known but a reaction has not yet occurred. Interventions attempt to reduce the possibility of the patient's encounter with the stressor or strengthen the flexible line of defense to decrease the possibility of a reaction when the stressor is encountered.
SECONDARY PREVENTION is the action required to attain system stability. Intervention involving secondary prevention is selected when a reaction to a stressor has already occurred. Interventions deal with existing symptoms and attempt to strengthen the lines of resistance through use of the patient's internal and external resources.
TERTIARY PREVENTION is the action required to maintain system stability. Intervention involving tertiary prevention is selected when some degree of patient system stability has occurred following secondary prevention interventions.
This page was last modified on 6/1/02